1. Field of the Invention
The present invention generally relates to management of a radio tag, and specifically relates to display of information on a terminal about an item to which a radio tag has been attached.
2. Description of the Related Art
Radio tags have already been widely used. To promote the radio tags further, it is necessary to reduce the cost of the radio tags. One approach to reduce the cost of the radio tags, apart from reducing the production costs or the costs for attaching the radio tags to items, is to produce revenue from the radio tags. One approach to produce such revenue is to display on a terminal an advertisement of the item, to which a radio tag is attached, when a customer is interested in that item.
For example, advertisements and tag IDs can be managed in a database, and when a customer tries to check the traceability information of a radio tag, an advertisement associated with a tag ID of that radio tag can be displayed on a terminal for the purchaser to see.
Japanese Patent Application Laid-Open No. 2003-224677 discloses a technology in which a radio tag communicates with a mobile telephone and causes the mobile telephone to display an advertisement.
In the conventional technology, however, private information can leak. Why and how the private information can leak is explained below with reference to FIG. 16.
As shown in FIG. 16, a radio-tag management device 20 manages tag information and tag IDs in associated manner for a plurality of radio tags. Each of the radio tag stores therein tag information relevant to itself along with its own tag ID.
For example, when the radio tag is in a production stage, only tag information A that is required in the production stage is stored in the radio tag. When the radio tag is in a distribution stage, only tag information B that is required in the distribution stage is stored in the radio tag. The radio-tag management device 20 manages all the tag information, such as tag information A, tag information B, tag information C, for all the radio tags for all the stages. As the stages change, tag information corresponding to the new stage is overwritten on the tag information of the previous stage in the radio tag. The tag information stored in a radio tag includes traceability information relating to an item to which the radio tag is attached. The traceability information includes information relating to producer and/or seller of the item.
An advertisement management device 10 manages tag IDs and advertisements in an associated manner for all the radio tags. Assume that a customer becomes interested in an item and tries to check traceability information, which is stored in a radio tag attached to the item, of the item by using a user's terminal 30. In this case, a tag ID of the radio tag attached to the item is sent to the advertisement management device 10 and the advertisement associated with the tag ID is fetched from the advertisement management device 10, and the advertisement is displayed on the user's terminal 30 together with the traceability information.
However, because the tag IDs are managed on the advertisement management device 10, a person who has access to the advertisement management device 10 can readily and fraudulently acquire traceability information of all the radio tags. Thus, the traceability information, which is private information, can readily leak to a third party.
Thus, there is a need of a technology that can prevent leakage of personal information in a radio tag system.